It is well known in the art of cutting metals by band saws that cutting efficiency, (or productivity; the terms are often used interchangeably) is a function of the several factors of saw cutting speed, accuracy of cut, and blade life. It is further well-known that these factors are related, and that one factor in a given environment can nearly invariably be improved, but always at the sacrifice of one or both of the other factors. Accuracy, which may be considered to be the ability to make a straight cut, may be increased at the sacrifice of cutting speed, for example, since, other factors remaining constant, accuracy can be improved by using a slower, more controlled cutting speed.
One of the most important elements which goes into efficient operation is the use of coolant. Indeed, coolant is such a sensitive factor that it may be said that use of proper coolant techniques can upgrade a relatively poorly performing machine to an excellently performing machine. Here again, however, good coolant practice, to this point in time, has been difficult to obtain--and maintain--in normal operations.
A cardinal principle of good coolant practice is to hold the coolant to the blade as long as possible; that is, it is desirable that coolant be available for application to the work piece at the downstream side of a long cut, as well as at the beginning of the cut. The advantages of holding coolant to the blade over substantially the entire cut, and the resultant increased production (which may be expressed in terms of an increased number of pieces per hour or other unit of time, more square inches cut per unit of time, or more square inches cut per blade) are well appreciated in the art. Specifically:
Holding coolant to the blade longer yields longer blade life. This end result reflects the decreased likelihood of welding chips to the blade, with resultant tooth breakage, which an adequate supply of coolant at all locations provides.
Holding coolant to the blade longer also permits the use of increased cutting forces (notably, heavier feeds) because the blade runs cooler than it otherwise would. Alternatively, or even in addition to, faster cutting speeds are made possible.
And finally, holding coolant to the blade longer provides additional lubricity over the entire cut, which in turn results in a more efficient power usage for a given feed, blade speed, and blade.
For all these reasons it is highly important to maximize coolant practices, and particularly the "hold" of the coolant to the blade throughout the full length of the cut.